I can sit at one of those meetings where the customer is annoyingly vague about his requirements and keeps waving his hands around as if it explains anything. I ask few questions, drilling down into specific requests he’s made and after the meeting, I tell my team: “The customer wants X. He forgot to ask for Y, but he’ll need this too. He’ll be very happy if we’ll throw in Z as well. He doesn’t need W, even though he asked for it, so we can skip it.”. I always get this right.